Strip mall client in Omaha served by OPPD. Five tenant spaces, all single-phase loads. But the service entrance is three-phase because one previous tenant had a commercial kitchen with three-phase equipment. That tenant left 4 years ago. OPPD is still billing the account on a three-phase demand tariff which has a higher demand rate than single-phase service. Can we get this reclassified?
Demand billing on three-phase vs single-phase ? common metering errors
Betty ? if all current loads are single-phase, the customer can request a service change to single-phase. OPPD would remove the three-phase transformer and install a single-phase one. But the property owner might resist if future tenants could need three-phase service. The cost of going back to three-phase later is significant.
Sharon ? good point about future flexibility. The property owner wants to keep three-phase capability for future tenants. Is there a way to get single-phase billing rates while keeping the three-phase service entrance?
Betty ? some utilities allow billing on actual service used rather than service available. If the meter shows all load on two phases with the third phase drawing zero, the billing should reflect single-phase usage. Check OPPDs tariff for provisions about billing based on actual service characteristics versus connected service.
Checked with OPPD. They bill based on service entrance configuration, not actual usage. Three-phase entrance = three-phase rate. Period. The only way to get single-phase rates is to physically convert to single-phase service. The property owner decided the future flexibility is worth the rate premium. But this is still a valid finding to document ? the premium is approximately $1,800 annually. If the property owner ever decides to convert, the savings are quantified and ready.
Postscript ? found another property in Omaha with the opposite problem. Single-phase service entrance with a three-phase motor installed by a tenant. The motor runs on a phase converter which draws significantly more power than direct three-phase service. The tenant would save $3,200 annually on demand charges by converting the service entrance to three-phase and eliminating the phase converter losses. Different problem, same root cause ? mismatched service and load.
Walter raises the right question. From the metering side, a three-phase meter measures demand across all three phases. If only two phases carry load, the meter still registers demand but typically at a lower reading than if all three phases were loaded. The tariff rate applied ? single-phase vs three-phase ? should match the actual service utilization. Some utilities have a provision for this; many do not and simply apply the rate based on the service entrance configuration.